Steam generator



June 3, 1 941. L. w. HELLER 2,243,852

STEAM GENERAT OR 7 Filed March 16, 1938 3 Sheets-Sheet 1 INVENTOR LewisWHe/ler June 3, 1941. w HELLER 2,243,862

STEAM GENERATOR Filed March 16, 1938 3 Sheets-Sheet 2 & l\ Q Q 00boooooooooono INVENTOR.

Lewis W Hal/e2 June 3, 1941.-

L w. HELLER 12,243,862

STEAM GENERATOR 7 Filed March 16, 1938 3 Sheets-Sheet 3 Fig 5 4/ W4? 59fi 6 13 12 25 I 139 D Mi Q 1 25 Q 24 i 26 27 z-%/w//mfi%' INVENTOE.Lewis WHe/[er ATTORNEY.

Patented June 3, 1941 STEAM GENERATOR Lewis W. Heller, East Orange, N. Jassignor to The Babcock & Wilcox Company, Newark, N. J., a corporationof New Jersey Application March 16, 1938, Serial No. 196,120

11 Claims.

This invention relates to the construction and operation of steamgenerators of the integral furnace type, i. e., a steam generator havingits furnace chamber laterally adjoining the main bank of steamgenerating tubes. In steam generators of this type the furnace chamberand space containing the main tube bank are usually separated except atone end, and the fuel burning means located at the opposite end of thefurnace chamber. Such an arrangement generally provides a path of flametravel of adequate length in the furnace chamber with some units usingcertain fuels and burners, but for higher steam generating and fuelburning capacities or limitations in the floor space available, or withother fuels or burners, a longer path of flame travel is desirable toinsure the desired completeness of combustion within the furnace chamberbefore the gases reach the tube bank and steam superheating tubes.

The main object of my invention is the provision of a steam generator ofthe type described with an improved construction and arrangement of thefurnace and tube bank chambers and associated fluid heating partsaffording a relatively long path of flame travel before the heatinggases enter the tube bank and a thermally effective heating gas flowover the convection heated surface, While maintaining a compactconstruction having low floor space and head room requirements.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof my invention.

Of the drawings:

Fig. 1 is a vertical section taken on the line -'-'l of Fig. 2illustrating somewhat diagrammatically one embodiment of the invention;

Fig. 2 is a horizontal section taken on the line 22 of Fig. 1;

Figs. 3 and 4 are longitudinal vertical sections taken on the lines 3-3and 5-4 respectively of Fig. 1; and

' Fig. 5 is a vertical section taken on the line 5-5 of Fig. 2.

The steam generating unit illustrated com prises a setting substantiallyrectangular inhorizontal and vertical cross-section including a front 5wall [0, a rear wall ll, side walls I2 and I3, and roof I4. A lower drum[5 is horizontally arranged along the lower part of the side Wall l3 andabove the bottom of the furnace chamber. A

. steam and water drum 16 extends parallel to the maining portionserving as the furnace chamber of the unit.

The furnace chamber is defined by the side wall I2 and portions of thewalls In and II and roof II. The furnace chamber walls are fluid cooled,the fluid cooling provisions comprising front wall tubes 89 and rearwall tubes 20' lining the front and rear walls respectively. The tubesl9 and 20 have their upper ends bent laterally into the upper drum I 6andtheir lower ends connected to headers 25 and22 respectively connectedto the drum l5. The side wall [2 and roof [4 are cooled by a row oftubes 23 extending from a lower side wall header 24 to the upper drumIS. The bottom of the furnace chamber is defined for substantially itsentire length by a fluid cooled floor 25 formed by a row of blockcovered tubes 26 extending from the header 24 toa similar header 2!below the drum [5. The floor 25 extends from the rear wall I l andterminates short of the front wall, the remaining portion of the furnacechamber bottom being formed by an ash pit 29.

The partition-forming means separating the furnace chamber from the tubebank space comprise a row of tubes 35 at the inner side of the tube bankextending downwardly from the drum IS. The tubes 35 in the rear portionof the tube row 35 continue downwardly and are connected to the'subjacent tubes 26 by incorporating an intermediate floor header 28 inthe rear portion of the tube row 26. The remaining tubes 35 are bentlaterally toward the drum l5 and thence along the lower portion l3 ofthe side Wall l3 to the header 21. The tubes 35 and 35 are partiallystudded to support refractory clos-' ing. the intertube spaces and thusform a partition 31 having a vertically extendin upper portion, avertical lower rear portion 31* and a laterally inclined front portion31 The partition construction described thus defines a furnace chamberhaving a laterally extending leg over a major portion of its length fromthe front wall rearwardly and an entrance into the tube bank spacebehind the partition section 31.

The partition construction described is especially adapted for theprovision of a relatively tubes in the tube now 23 are bent, as shown inFig. 3, in an inclined plane in spaced relation across the burner port.A pair of pulverized fuel burner nozzles M of the multiple-outlet typeare arranged side-by-side in the burner port with the burner outletshaving their longitudinal axes intersecting the axes of thecorresponding tube portions, whereby the streams of primary air andpulverized fuel issuing from the nozzles are divided by the subjacenttube portions and pass through the intertube spaces into the furnacechamben A secondary air casing 42 encloses the burner nozzles 4| andburner port 40 and provides a stream of. secondary air around the burneroutlets and through the inter-tube spaces. With this constructionstreams of pulverized fuel and combustion air are directed downwardlyand forwardly in the furnace chamber. Combustion will proceed at arelatively rapid rate, and the products of combustion flow laterallybelow the partition section 31 and rearwardly behind the partitionsection 3'! into the bottom of the' tube bank space. Y

The tube bank space is advantageously divided into a plurality ofserially connected passes by the baffle system hereinafter described. Asshown in Fig. 1, the tubes ll forming the outermost row of tubes havetheir upper portions bent laterally to the side wall l3 before enteringthe drum. l6. Bafile blocks are arranged to form a baffle 45 followingthe configuration of. the tubes I! from the lower drum l5 to the upperpart of the rear wall l3,the bent upper portion of the tubes I'I servingto support the baffle blocks. The baffle 45 extends from the front wallrearwardly to the same extent as the partition section 31*. A verticalbafile 461 extends downwardly through the tube bank to its full extentand laterally from the partition 31 to the full width of the tube bank,and also closes the rear end of the space within the baffle 45. Thespace between the baffle 4B and the rear wall ll forms a gas pass 50through which the heating gases flow upwardly and then forwardly throughthe triangular space defined by the upper portions of the tubes H at theouter side of the bafile 46. This triangular space is closed at 'a pointforwardly of the battle 46 by a second transverse baflle 41 which alsoextends the full width of the tube bank and terminates atits lower endacross the inclined portion of the tubes ll, as indicated in Fig.1. Thebafile 41 thus divides the space forwardly of the baflle 46 into asecond pass 5|. through which the heating gases flow downwardly andlaterally, and a third gas pass 52 through which the heating gases flowlaterally and upwardly to a gas outlet 53 at the front end of the tubebank space.

The portion of the tube bank I! in the first gas pass 50 is formed by asmall number of tube rows I'l of larger diameter than the remainingtubes in the bank. The inclined portions of the tubes in the two lowerrows l'l are spaced and arranged, as shown in Fig. 4, to provide a slagscreen across the entrance to the first pass 50.

- over the baffle 35 into the second pass 5|.

The remaining portion of the gas pass is 00- cupied by a group ofvertical superheater tube coils arranged in a multiple horizontalloopedi formation. Each superheater tube coil has its; horizontallyextending legs interconnected by; supporting lugs 56 and the coil issuitably sup-- ported as a whole at opposite ends from the: adjacenttubes ll and wall IS. The upper ends: of the superheater tube coils 55are connected! to the steam space of the drum l6, while their: lowerends are connected to the steam main.. With this arrangement of theheating surface in: the first pass the heating gases flow upwardly/ overthe tubes IF and superheater tubes, then: around the upper portion ofthe bafile 46 and. The: gases flow downwardly therein along the tubes:I! and around the lower end of the bafile 41 into the third pass 52,wherein the gases flow upwardly through the tube bank opposite to thegas flow in the pass 5i.

With the arrangement of the generating tubes; N and superheater coilsillustrated, the heating gases flowing upwardly through the first pass50 may tend to short-circuit part of the superheating surface due to thegreater gas flow area in the pass adjacent the partition 31. Thedistribution of the heating gases and thereby the amount of superheatingeffected is controlled, as shown in Fig. 5, by the arrangement of avertical baflie 58 at the inner end of the superheater coils. The baiiledivides the gas pass 50 longitudinally and terminates short of the drum16, with the space therebetween controlled by a pivoted damp-- er 59adapted to be externally operated. The position of. the damper willcontrol the amount of heating gases passing upwardly between thepartition 31 and baflle 58.

- The described steam generator construction provides a somewhatreverberatory flame path of substantial length in the furnace (:hamber,which expedites combustion and insures an adequate length of flametravel at high rates of fuel introduction. The particular tube bank andbaflle formation employed permits this long flame path in the furnacechamber, and also provides a. thermally effective flow of heating gasesconvection heated surface.

While in accordance with the provisions of the statutes'I haveillustrated and described herein the best form of my invention now knownto me,

nace chamber extending along the outer side of and partly below theL-shaped space containing said tube bank and communicating there withadjacent one end thereof, and means for burning fuel in said furnacechamber and causing a flow of heating gases from said furnace chamberlongitudinally of the L-shaped space containing said tube bank.

2. A steam generator comprising an upper horizontally elongated drum anda laterally dis-- over the placed lower drum, a bank of L-shaped steamgenerating tubes connecting said drums, partition means separating thespace containing said L-shaped tube bank from one side of a furnacechamber extending along one side of and partly below the spacecontaining said tube bank and communicating therewith adjacent one endthereof only, and means at the communicating end of said furnace chamberfor discharging a stream of fluid fuel in said furnace chamber andburning the fuel in suspension therein.

3. A steam generator comprising an upper horizontally elongated drum anda laterally displaced lower drum, a bank of L-shaped steam generatingtubes connecting said drums, partition means defining one side of afurnace chamber extending along one side of and partly below the spacecontaining said tube bank and communicating therewith adjacent one endthereof only, means at the communicating end of said furnace chamber fordischarging a stream of fluid fuel in said furnace chamber and burningthe fuel in suspension therein, and means defining a plurality ofserially connected vertical gas passes longitudinally of said tube bank.

4. A steam generator comprising an upper horizontally elongated drum anda laterally displaced lower drum, a bank of L-shaped steam generatingtubes connecting said drums, means defining a furnace chamber extendingalong one side of and partly below the space containing said tube bankand communicating therewith adjacent one end thereof only, said meanscomprising a fluid cooled partition extending downwardly from said upperdrum and divided into a portion extending laterally below said tube bankand a portion extending vertically to the bottom of said furnacechamber, and means for burning fuel in suspension in said furnacechamber.

5. A steam generator comprising an upper horizontally elongated drum anda laterally displaced lower drum, a bank of L-shaped steam generatingtubes connecting said drums, means defining a furnace chamber extendingalong one side of and partly below the space containing said tube bankand communicating therewith adjacent one end thereof only, said meanscomprising a row of partition-forming water tubes extending downwardlyfrom said upper drum and divided into a group of L-shaped tubesextending laterally below said tube bank and a group of vertical tubesextending to the bottom of said furnace chamber, means closing theintertube spaces of said partition tubes, and means for burning fuel insaid furnace chamber.

6. A steam generator comprising an upper horizontally elongated drum anda laterally displaced lower drum, a bank of L-shaped steam generatingtubes connecting said drums, means defining a furnace chamber extendingalong one side of and partly below the space containing said tube bankand communicating therewith adjacent one end thereof only, said meanscomprising a partition extending downwardly from said upper drum andhaving a portion extending laterally below said tube bank, means forburning fuel in said furnace chamber, and means defining a plurality ofserially connected vertical gas passes longitudinally of the spacecontaining said tube bank.

'7. A steam generator comprising an upper horizontally elongated drumand a laterally displaced lower drum, a bank of L-shaped steamgenerating tubes connecting said drums, means defining a furnace chamberextending along one side of and partly below the space containing saidtube bank and communicating therewith adjacent one end thereof only,said means comprising a partition extending downwardly from said upperdrum and having a portion extending laterally below said tube bank and aportion extending vertically to the bottom of said furnace chamber,means for burning fuel in said furnace chamber, and means defining aplurality of serially connected vertical gas passes longitudinally ofthe space containing said tube bank, said last named means including ahorizontally disposed V-shaped baffle at the opposite side of said tubebank, and a pair of vertically disposed baffles extending between saidpartition and said V-shaped baffle.

3. A steam generator comprising an upper horizontally elongated drum anda laterally displaced lower drum, a bank of L-shaped steam generatingtubes having laterally extending lower portions connected to the lowerdrum and vertically extending upper portions connected to the upperdrum, means separating the space containing said L-shaped tube bank froma furnace chamber extending along one side of and partly below the spacecontaining said tube bank, said means including a partition extendingdownwardly from said upper drum at the furnace chamber side of said tubebank and having a lower portion extending laterally below said tubebank, a heating gas outlet from said furnace chamber into said tube bankspace arranged below said laterally extending tube portions andproviding a heating gas flow upwardly across said laterally extendingtube portions, and means for burning fuel in said furnace chamber.

9. A steam generator having walls forming a setting, a horizontallyelongated steam and water drum, means forming a furnace chamber in saidsetting having a lateral extension and partly separated from aconvection space in said setting located above said furnace chamberextension, said means including L-shaped steam generating tubes havingvertically extending upper portions connected to said drum and closuremeans cooperating with said L-shaped tubes to form a partition extendingdownwardly from said drum at the furnace chamber side of saidconvectionspace and having a lower portion extending laterally below saidconvection space, a gas outlet in said partition lower lateral portion.connecting said furnace chamber extension to said convection space,fluid heating tubes arranged in said convection space, and baffle meansdividing said convection space into serially connected upflow anddownflow heating gas passes below the level of said drum and containingsaid fluid heating tubes.

10. A steam generator having walls forming a setting, a horizontallyelongated steam and water drum, means forming a furnace chamber in saidsetting having a lateral extension and partly separated from aconvection space in said setting located above said furnace chamberextension, said means includin L-shaped steam generating tubes havingvertically extending upper portions connected to said drum and closuremeans cooperating with said L-shaped tubes to form a partition extendingdownwardly from said drum at the furnace chamber side of said convectionspace and having a lower portion extending laterally below saidconvection space, a gas outlet at one end of said partition lowerlateral portion connecting said furnace chamber extension to saidconvection space, baflie means dividing said convection space into anupfiow heating gas pass opening to said gas outlet and a seriallyconnected downflow heating gas pass extending below the level of saiddrum, fluid heating tubes located in said heating gas passes, and agroup of said L-shaped tubes having their lower portions arranged toform a tube screen across said gas outlet.

11. A steam generator having walls forming a. setting, a horizontallyelongated steam and water drum, means forming a furnace chamber in saidsetting having a lateral extension and partly separated from aconvection space in said setting located above said furnace chamberextension, said means including L-shaped steam generating tubes havingvertically extending upper portions connected to said drum and closuremeans cooperating with said L-shaped tubes to form a partition extendingdownwardly from said drum at the furnace chamber side of said convectionspace and having a lower portion extending laterally below saidconvection space, a gas outlet from said furnace chamber extensionupwardly into said convection space, fluid heating tubes arranged insaid convection space, baflles dividing said convection space intoserially connected upfiow and downflow heating gas passes containingsaid fluid heating tubes, a bank of steam heating tubes located in anupflow pass opening to said gas outlet, and a damper controlled by-passpassage arranged in parallel with said upflow pass.

LEWIS W. HELLER.

